An open trial of pyridostigmine in post-poliomyelitis syndrome.

BACKGROUND: One of the major symptoms of postpoliomyelitis syndrome (PPS) is disabling generalized fatigue. Subjects with PPS also report muscle fatiguability and display electrophysiologic evidence of anticholinesterase-responsive neuromuscular junction transmission defects, suggesting that anticholinesterase therapy may be useful in the management of disabling fatigue.
METHODS: We initiated an open trial of the oral anticholinesterase pyridostigmine, up to 180 mg per day, in 27 PPS patients with generalized fatigue and muscle fatiguability. Response to pyridostigmine was assessed with the Hare fatigue scale, the modified Barthel index for activities of daily living, and a modified Klingman mobility index.
RESULTS: Two patients could not tolerate the medication. After one month of therapy, 16 patients (64%) reported a reduction in fatigue on the Hare fatigue scale; three of 16 showed improvement on the modified Barthel index for activities of daily living, and two of 16 experienced improvement on a modified Klingman mobility index. Pyridostigmine responders were significantly more fatigued than non-responders on the pre-treatment Hare score, but were not significantly different with regard to age, sex, age at acute poliomyelitis, or severity of acute poliomyelitis.
CONCLUSIONS: Pyridostigmine may be useful in the management of fatigue in selected patients with PPS. Response to pyridostigmine may be predicted by severity of pre-treatment fatigue.